Bug summary

Matplotlib generates as a side-effect a font cache during import time. This is needed for plotting functionality to work. Unfortunately, this also means that any (transitive) dependency that eagerly imports matplotlib will now result in the cache to be generated, even when the user is at no time using matplotlib.

I opened an issue about this 8 years ago #7592. At the time the issue was regarding Linux. Now, it seems the behaviour has changed on MacOS and it happens there as well.

Code for reproduction

import matplotlib

Actual outcome

/nix/store/774r81hjzn2p64jnsdyk0cl2rbjabghj-python3-3.12.3-env/lib/python3.12/site-packages/matplotlib/font_manager.py:270: in _get_macos_fonts
    subprocess.check_output(["system_profiler", "-xml", "SPFontsDataType"]))
/nix/store/65ackbgqn02p6fy75rksjbp17zj6440j-python3-3.12.3/lib/python3.12/subprocess.py:466: in check_output
    return run(*popenargs, stdout=PIPE, timeout=timeout, check=True,
/nix/store/65ackbgqn02p6fy75rksjbp17zj6440j-python3-3.12.3/lib/python3.12/subprocess.py:548: in run
    with Popen(*popenargs, **kwargs) as process:
/nix/store/65ackbgqn02p6fy75rksjbp17zj6440j-python3-3.12.3/lib/python3.12/subprocess.py:1026: in __init__
    self._execute_child(args, executable, preexec_fn, close_fds,
/nix/store/65ackbgqn02p6fy75rksjbp17zj6440j-python3-3.12.3/lib/python3.12/subprocess.py:1955: in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
E   FileNotFoundError: [Errno 2] No such file or directory: 'system_profiler'

Expected outcome

Preferably no side-effect during import-time. Or, as a work-around, some option such as an environment variable to disable the side-effect.

Additional information

Obviously if packages would not import matplotlib eagerly this would not be an issue. However, as a end-user this cannot be controlled. Anywhere in the dependency-tree one could import a library that is not required per se. But that does not mean libraries should just do side-effects during import time. Having an environment variable to disable the cache building would already be great, as it would provide a way out, other than trying to patch a (transitive) dependency.

Operating system

OSX

Matplotlib Version

3.9.0

Matplotlib Backend

No response

Python version

3.12

Jupyter version

No response

Installation

None